A safety razor, designed to protect the user from serious injury, is a razor where the facial skin is protected from all but the very edge of the blade. Prior to using a safety razor, most men used a straight razor. These razors, although still available today, are not used very often due to the skill and attention required for use.
Jean-Jacques Perret invented the safety razor. A rare safety razor design called "Comfort", although not truly a safety razor, was a landmark design. In...

A pivoted catch designed to fall into a notch on a ratchet wheel so as to allow movement in only one direction (e.g. on a windlass or in a clock mechanism), or alternatively to move the wheel in one direction.